Free-Floating Watercraft Lift

ABSTRACT

A free-floating watercraft lift includes a plurality of pairs of tanks each having a first tank and a second tank, a plurality of lower frame assemblies, first and second upper frame assemblies, and a control system comprising at least one blower for selectively providing air to each of the first and second tanks of the plurality of pairs of tanks. The first and second tanks of each pair of tanks are laterally spaced-apart and facing one another. Each one of the lower frame assemblies connects the first tank and the second tank of a separate one of the pairs of tanks The first upper frame assembly connects each of the first tanks of the plurality of pairs of tanks and the second upper frame assembly connects each of the second tanks of the plurality of pairs of tanks.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Patent Application No. 63/090,100 filed on Oct. 9, 2021, the disclosure of which is expressly incorporated herein in its entirety by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable

PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

REFERENCE TO APPENDIX

Not applicable

FIELD OF THE INVENTION

The field of the present invention generally relates to watercraft lifts, and more particularly, to watercraft lifts that are free floating and use air displacement to raise and lower the watercraft.

BACKGROUND OF THE INVENTION

The use of air displacement type, free-floating watercraft lifts is known. See for example, but not limited to, U.S. Pat. Nos. 9,199,705, 8,683,934, 7,325,503, 7,246,970, 7,096,809, 6,823,809, and 6,422,167, the disclosures of which are expressly incorporated herein in their entireties.

These free-floating watercraft lifts use a plurality of tanks that are connected to a blower. Initially, the tanks contain water so that they are at least partially submerged in the water enough that the watercraft can be moved over the top of the tanks. To lift the watercraft, the blower is activated to blow air into the tanks to displace the water in the tanks enough so that the tanks rise due to buoyancy and lift the watercraft out of the water.

While these known watercraft lifts are generally effective at lifting watercraft out of the water, they continue to have problems. For example, but not limited to, the problems include difficulty maintaining stability during lifting and launching, low strength, difficult and/or lengthy assembly, difficulty adjusting for different size boats, and difficulty shipping or transporting between locations.

Accordingly, there continues to be a need for improved free-floating, air-displacement type watercraft lifts.

SUMMARY OF THE INVENTION

The present invention provides free-floating displacement-type watercraft lifts which address at least one of the above-noted problems of the prior art. Disclosed herein is a free-floating watercraft lift comprising, in combination, a plurality of pairs of tanks each having a first tank and a second tank, a plurality of lower frame assemblies, first and second upper frame assemblies, and a control system comprising at least one blower for selectively providing air to each of the first and second tanks of the plurality of pairs of tanks. The first and second tanks of each pair of tanks are laterally spaced-apart and facing one another. Each one of the lower frame assemblies connects the first tank and the second tank of a separate one of the pairs of tanks. The first upper frame assembly connects each of the first tanks of the plurality of pairs of tanks arid the second upper frame assembly connects each of the second tanks of the plurality of pairs of tanks.

Also disclosed is a free-floating watercraft lift comprising, in combination, a plurality of pairs of tanks each having a first tank and a second tank, a plurality of lower frame assemblies, first and second upper frame assemblies, and a control system comprising at least one blower for selectively providing air to each of the first and second tanks of the plurality of pairs of tanks. The first and second tanks of each pair of tanks are laterally spaced-apart and facing one another. Each of the first and second tanks are generally L shaped such that a height of the laterally outward side is greater than the height of the laterally inward side Each one of the lower frame assemblies connects the first tank and the second tank of a separate one of the pairs of tanks. Each of the lower frame assemblies include a first tank frame secured to the first tank and a second tank frame secured to the second tank, and a pair of horizontal and spaced-apart bunk arms each extending between the first tank frame and the second tank frame. The first upper frame assembly connects each of the first tanks of the plurality of pairs of tanks and the second upper frame assembly connects each of the second tanks of the plurality of pairs of tanks. The first upper frame assembly includes a pair of horizontal and laterally spaced-apart first beams extending across and secured to each of the first tanks, and the second upper frame assembly includes a pair of horizontal and laterally spaced-apart elongate second beams extending across and secured to each of the second tanks. Each of the first and second tanks includes a generally horizontal top support surface along a laterally outward side that is upward facing for the beams of the first and second upper frame assemblies, and horizontal lower support surfaces along forward and rearward sides that are upward facing for the first and second tank frames, and wherein the lower support surfaces are located between a top and a bottom of the first and second tanks.

From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of free-floating, displacement-type watercraft lifts. Particularly, significant in this regard is the potential the invention affords for providing a reliable and effective watercraft lift that can be easily adjusted for different sized watercraft and can be easily transported on a standard size trailer, Additional features and advantages of the invention will be better understood in view of the detailed description provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further objects of the invention will become apparent from the following detailed description.

FIG. 1 is a perspective view of a free-floating watercraft lift according to the present invention, wherein some components have been removed for clarity,

FIG. 2 is a perspective view of the free-floating watercraft lift of FIG. 1 wherein some components have been removed for clarity.

FIG. 3 is an enlarged perspective view of a tank of the free-floating watercraft lift of FIGS. 1 and 2 with a tank frame secured thereto.

FIG. 4 is an enlarged fragmented view taken from line 4 in FIG. 3 showing a portion of the tank frame with a pair of clamps secured thereto.

FIG. 5 is a perspective view of a lower frame assembly of the free-floating watercraft lift of FIGS. 1 and 2 with one tank frame removed for clarity.

FIG. 6 is an enlarged fragmented view taken from line 6 in FIG. 5 showing a portion of the frame assembly with a clamp and a bunk bracket secured thereto.

FIG. 7 is a perspective view of a clamp of the frame assembly of FIGS. 4 and 5.

FIG. 8 is a perspective view of a bunk bracket of the frame assembly of FIGS. 4 and 5.

FIG. 9 is an exploded perspective view of a top frame assembly of the free-floating watercraft lift of FIGS. 1 and 2 with one tank walkway plank removed for clarity.

FIG. 10 is an enlarged fragmented view taken from line 10 in FIG. 9 showing a portion of the top frame assembly at a bushing bracket and bushing.

FIG. 11 is bottom view of a tank walkway plank of FIGS. 9 and 10.

FIG. 12 is side view of the tank walkway plank of FIG. 12.

FIG. 13 is a diagammatic view of a control system of the free-floating watercraft lift of FIGS. 1 and 2.

FIG. 14 is a perspective view of a controller post with mounting plate of the free-floating watercraft lift of FIGS. 1 and 2.

FIG. 15 is a front view of a controller of the free-floating watercraft lift of FIGS. 1 and 2.

FIG. 16 is a front view of a power switch located within the controller of FIG. 15.

FIG. 17 is a perspective view of the free-floating watercraft lift of FIGS. 1 and 2 in a submerged position next to a boat dock such that only the tank walkway planks, the controller post, and the controller of the free-floating watercraft lift are located above the water.

FIG. 18 is a perspective view of the free-floating watercraft lift of FIGS. 1 and 2 in a floating position with a watercraft thereon lifted out of the water next to a boat dock.

FIG. 19 is a perspective view of free-floating watercraft lift according to a first variation of free-floating watercraft lift of FIGS. 1 and 2, wherein the free-floating watercraft lift includes three pairs of tanks rather than two pairs of tanks.

FIG. 20 is a perspective view of free-floating watercraft lift according to a second variation of free-floating watercraft lift of FIGS. 1 and 2, wherein the free-floating watercraft lift includes four pairs of tanks rather than two pairs of tanks.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the various free-floating watercraft lifts as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration, All references to direction and position, unless otherwise indicated, refer to the orientation of the free-floating watercraft lifts illustrated in the drawings. In general, up or upward generally refers to an generally upward direction within the plane of the paper in FIG. 1 and down or downward generally refers to a generally downward direction within the plane of the paper in FIG. 1. Also in general, fore or forward generally refers to a generally outward direction out the plane of the paper in FIG. 1 and aft or rearward generally refers to a generally inward direction into the plane of the paper in FIG. 1.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS

It will be apparent to those skilled in the art, that is, to those who have knowledge or experience in this area of technology, that many uses and design variations are possible for the free-floating watercraft lifts disclosed herein. The following detailed discussion of various alternative and preferred embodiments will illustrate the general principles of the invention with regard to the specific application of free-floating, air-displacement type watercraft lifts. Other embodiments suitable for other applications will be apparent to those skilled in the art given the benefit of this disclosure.

FIGS. 1 and 2 illustrate a free-floating, air-displacement type watercraft lift 10 according to the present invention. The illustrated watercraft lift 10 includes a plurality of pairs of tanks 12 each pair having a first tank 14 a and a second tank 14 b, a plurality of lower frame assemblies 16, first and second upper frame assemblies 18 a, 18 b, and a control system 20 comprising at least one blower 22 (best shown in FIG. 13) for selectively providing air to each of the first and second tanks 14 a, 14 b of the plurality of pairs of tanks 12. The first and second tanks 14 a, 14 b of each pair of tanks 12 are laterally spaced-apart and facing one another and spaced apart in the forward /rearward direction from any adjacent pairs of tanks 12. Each one of the lower frame assemblies 16 connects the first tank 14 a and the second tank 14 b of a separate one of the pairs of tanks 12. The first upper frame assembly 18 a connects each of the first tanks 14 a of the plurality of pairs of tanks 12 and the second upper frame assembly 18 b connects each of the second tanks 14 b of the plurality of pairs of tanks 12. The illustrated watercraft lift 10 has two pairs of tanks 12 for a total of four tanks 14 a, 14 b. Thus there are two lower bracket assemblies 16. However, it is noted that any other suitable quantity of pairs of tanks 12 can alternatively be utilized as described in more detail herein below (best seen in FIGS. 19 and 20).

As best shown in FIGS, 2 and 3, the illustrated first and second tanks 14 a, 14 b are identical and each first and tank 14 a, 14 b is generally “L” shaped such that a height of the laterally outward side is greater than the height of the laterally inward side. A generally fiat and horizontally extending upper support surface 24 is provided along the laterally outward side that is upward facing to provide a support for one of the first and second upper bracket assemblies 18 a, 18 b. Additionally, generally flat and horizontally extending lower support surface segments are provided along the forward, rearward, and laterally inward sides of the tank that are upward facing to provide support for a portion of the lower frame assemblies 16 as discussed in more detail below. These three lower support surface segments combine to form a continuous U-shaped lower support surface 26. The lower support surface 26 is located between the top and bottom of the tanks 14 a, 14 b. Vertically extending abutments 28 are provided at the outward edges of the lower support surface 26 and tank walls 30 are located at the inner edges of the lower support surface 26 so that the entire periphery of the U-shaped support surface is surrounded by a combination of the abutments 28 and the tank walls 30.

The illustrated tanks 14 a, 14 b are each general hollow and rotationally molded of polyethylene. The tanks 14 a, 14 b can have any suitable capacity. The tanks 14 a, 14 b each have at least one air opening 32 and at least one water outlet 34 (best shown in FIG. 13). The air openings are provided with molded-in air fitting threads to eliminate leaks which are common when fair fittings are attached with spin welds. It is noted that while a preferred embodiment is shown and described, the tanks I 4 a, 14 b can alternatively have any other suitable size, shape, material, and/or configuration,

As best shown in FIGS. 3 to 6, each illustrated lower frame assembly 16 includes first and second tank frames 36 a, 36 b, two bunk arms 38, a plurality of clamp assemblies or claws 40, and a plurality of bunk bracket assemblies or bunk brackets 42. The illustrated first and second tank frames 36 a, 36 b are identical. The first tank frame 36 a is secured to the first tank 14 a on the U-shaped lower support surface 26 and the second tank frame 36 b secured to the second tank 14 b on the U-shaped lower support surface 26. The pair of horizontal and spaced-apart bunk arms 38 each extend between the first tank frame 36 a and the second tank frame 36 b and are secured to each tank frame 36 a, 36 b to secure the pair of tanks 14 a, 14 b together. The illustrated lower frame assembly 16 is formed of aluminum components along with stainless steel hardware. It is noted that while a preferred embodiment is shown and described, the lower frame assembly 16 can alternatively have any other suitable size, shape, material, and/or configuration.

Each of the illustrated U-shaped tank frames 36 a, 36 b include a pair of first frame members 44 and a single second frame member 46. Each of the first and second frame members 44, 46 are elongate and channel shaped having a bottom wall and opposed side walls upwardly extending from the opposite sides of the bottom wall to form an open top opposite the bottom wall. The first frame members 44each have one end secured to opposite ends of the second frame member 46 so that the first frame members 44 are perpendicular to the second frame member 46 and parallel with each other. Secured together in this manner, the first and second frame members form the U-shaped tank frames 36 a, 36 b with the ends of the channels of the first frame members 44 open and the ends of the channel of the second fame member 46 closed by the first frame members 44

The U-shaped tank frames 36 a, 36 b are secured to the U-shaped support surfaces 26 of the tanks 14 a, 14 b between the abutments 28 and the tank walls 30. Attaching the U-shaped tank frames 36 a, 36 b around the perimeters of the tanks 14 a, 14 b provides additional strength and ease of manufacturing. Each of the illustrated first frame members 44 is provided with a pair of the clamps 40 for cooperation with one of the bunk arms 38 as described in more detail herein below. Therefore the illustrated U-shaped tank frames 36 a, 36 b each utilize four clamps 40. it is noted that any other suitable quantity of the clamps 40 can alternatively be utilized. The illustrated first frame members 44 each have a plurality of spaced apart and aligned openings 48 along each of the side walls near a top of the side walls. The openings 48 permit the clamps 40 to be selectively secured at different locations along the length of the first frame members 44 as describe in more detail hereinafter. It is noted that while a preferred embodiment is shown and described, the U-shaped tank frames 36 a, 36 b can alternatively have any other suitable configuration.

The illustrated bunk arms 38 are each elongate and channel shaped having a top wall and a pair of side walls downwardly extending form opposed edges of the top wall to form an open bottom side. The bunk arms 38 are horizontal and laterally extend between the two U-shaped tank frames 36 a, 36 b secured to the pair of tanks 12. The bunk aims 38 are sized and shaped to be slidably received in the channels of the first frame members 44 of the first and second U-shaped tank frames 36 a, 36 b. The illustrated bunk arms 38 each have a width that can be received between the side walls of the first frame members 44 and height that permits the bunk arm 50 to extend below the clamps 40 secured to the side walls of the first frame members 44. The bunk arms 38 are adjustably secured to each of the first frame members by the damps 40 as described in more detail below. As a result, a lateral distance between the first and second tanks 14 a, 14 b of a pair of tanks 12 is infinitely adjustable between the minimum and maximum set by the length of the bunk arms 38 in order to account for different sized boat widths. The bunk arms 38 can be repositioned within the first frame members 44 of the U-shaped tank frames 36 a, 36 b in a telescoping manner when the clamps 40 are loose or unlocked and the positions of the bunk arms 38 within the second frame members 44 of the U-shaped tank frames 36 a, 36 b are locked when the clamps 40 are tight or locked. The U-shaped tank frames 38 a, 38 b and the bunk arms 38 are provided with lengths adequate to accommodate one or more desired boat widths. The illustrated bunk arms 38 each have two separate sets of a plurality of spaced apart and aligned openings 50 along each of their side walls. The openings 50 permit the bunk brackets 42 to be selectively secured at different locations along the length of the bunk arms 38 as describe in more detail hereinafter. It is noted that configured in this manner, the first and second tanks 14 a, 14 b and lower frame assembly 16 have an integral monocoque design. It is noted that while a preferred embodiment is shown and described, the bunk arms 38 can alternatively have any other suitable configuration.

As best shown in FIG. 7, the illustrated clamp assembly or clamp 40 includes a body 52 in the shape of a channel having a bottom wall and a pair of side walls upwardly extending from opposed sides of the bottom wall to form an open top opposite the bottom wall and open ends. The width of the body 52 is sized to closely fit between the side walls of the first frame members 44. A threaded nut 54 is secured at the top of the bottom wall at an opening in the bottom wall and a threaded fastener 56 is threaded downward through the nut 54 and opening so that its lower end can be raised and lowered by turning a head of the threaded fastener 56. A pair of aligned openings 58 are provided in the side walls so that a pin 60 can horizontally extend therethrough and be secured therein by a spring clip 62 extending through an opening 64 in the free end of the pin 60 opposite a head of the pin. The illustrated spring clip 62 is an R-Clip but any other suitable type of spring clip 62 can alternatively be utilized. In operation, the clamp 40 is secured to the first frame member 44 by placing the body 52 within the first frame member 44 above the bunk arm 38 and aligning the openings 58 with a desired pair of openings 48 in the first frame member 44 so that the pin 60 can be extended through the openings 48,58. The spring clip 62 is secured to the free end of the pin 60 so that the body 52 is secured to the first frame member 44 at the desired position. The threaded fastener 56 is raised out of engagement with the top wall of the bunk arm 38 so that the position of the bunk arm 38 can be adjusted. To clamp or secure the bunk arm 38 to the first frame member 44, the threaded fastened 56 is threaded down into engagement with the bunk arm 38 to clamp the bunk arm 38 between the threaded fastener 56 and the bottom wall of the first frame member 44. It is noted that while a preferred embodiment is shown and described, the clamp 40 can alternatively have any other suitable configuration.

As best shown in FIG. 8, the illustrated bunk bracket assembly or bunk bracket 42 includes a body 66 having an inner wall and a front and back walls laterally outwardly extending from opposed front and back sides of the inner walk The width of the body 66 is sized to closely fit over the side walls of one of the bunk arms 38. A plurality of vertically spaced apart openings 68 are provided in the inner wall. The openings 68 are sized and spaced to cooperate with a bunk 70 to secure the bunk t70 o the bunk bracket 42, A pair of aligned openings 72 are provided in the side walls near the bottom so that a pin 74 can horizontally extend therethrough and he secured therein by a spring clip 76 extending through an opening 78 in the free end of the pin 74 opposite a head of the pin 74. The illustrated spring clip i76 s an R-Clip but any other suitable type of spring clip 76 can alternatively be utilized. In operation, the bunk bracket 42 is secured to one of the bunk arms 38 by placing the body 66 over the bunk arm 38 and aligning the pair of openings 72 with a desired pair of the openings 50 in the bunk arm 38 so that the pin 74 can be extended through both pairs of the openings 50, 72. The spring clip 76 is secured to the free end of the pin 74 so that the body 66 is secured to the bunk arm 38 at the desired position, it is noted that while a preferred embodiment is shown and described, the bunk brackets 42 can alternatively have any other suitable configuration.

A pair of horizontal and laterally spaced-apart bunks 70 are secured to and supported by the plurality of bunk brackets 42 (best shown in FIG. 1). The illustrated bunk brackets 42 are adjustably secured along the lengths the of the bunk arms 38 between the first frame members 44, As a result, a lateral distance between the pair of bunk brackets 42, and thus bunks 70, is adjustable for different sized boat widths by repositioning the bunk brackets 42 along the bunk arms 38.

The illustrated bunks 70 are each generally elongate and are sized and shaped to be secured to the bunk brackets 42 so that they extend along the length of the watercraft lift 10 in a parallel manner. On the illustrated watercraft lift 10, each bunk bracket 42 is secured to one of the four bunk arms 38. The bunks 70 have a suitable size, shape, and material to engage and support the watercraft when it is raised by the lift 10. It is noted that while a preferred embodiment is shown and described, the bunks 70 can alternatively have any other suitable configuration.

As best shown in FIGS. 9 to 12, the illustrated first and second upper frame assemblies 18 a, 18 b each include a pair of walkway supports or beams 80 and at least one walkway plank or panel 82 secured to the beams 80 to form a walkway 84 over each of the pairs tanks 12. The illustrated beams 88 are elongate square tubes. A pair of laterally spaced-apart beams 80 are each secured to the upper support surfaces 24 of the tanks 14 a, 14 b on each side of the watercraft lift 10 so that there are four of the beams 80 in total. The illustrated walkways 84 are formed by a pair of the walkway planks 82 but any other suitable quantity can be utilized (for example see FIGS. 19 and 20). The illustrated walkway planks 82 are each elongate panels having a generally horizontal upper and lower surfaces. The walkway planks 82 are each secured to the pair of beams 80 so that there is one of the walkways 84 on each lateral side of the watercraft lift 10 that extends the length of the watercraft lift 10. The walkways 84 are positioned at the top of the tanks 14 a, 14 b so that the walkways 84 are still positioned above the water when the tanks 14 a, 14 b are submerged (best shown in FIG. 17). it is noted that the walkway beams 80 and the walkway planks 82 also secure the two pairs of tanks 12 together to make the overall structure stronger and more rigid.

The illustrated walkway planks 82 are secured to the beams 80 by walkway brackets 86 secured to the bottom surface of the walkway planks 82 which cooperate with bushings 88 secured to the inner sides of the beams 80. The illustrated walkway planks 82 each have three spaced-apart brackets 86 secured to the lower surface of each plank 82. Each of the walkway brackets 86 has a pair of laterally spaced-apart slots 90. The slots 90 are each horizontally extending with an open end 92 and a closed end 94 and are sized to receive one of the bushings 88 therein. The walkway brackets 86 drop down between the two beams 80, and are then slid in a forward direction to catch the bushings 88 that are attached to the inside of both beams 80 into the slots 90. Secured in this manner, movement of the walkway plank 82 relative to the beams 80 is limited in each direction except the horizontal and longitudinal rear direction which is the direction that the bushings 90 exit the slots 90. The walkway plank 82 is then locked in place by the next walkway plank 82 inserted behind it which blocks rearward relative movement of the first inserted walkway plank.82. The last inserted walkway plank 82 is locked in place against rearward movement by one mechanical fastener such as, for example but not limited to, a bolt or the like. This attachment system allows for quick assembly/disassembly of the entire walkway 84 with only one mechanical fastener holding the entire length of the plurality of walkway planks 82 in place. It is noted that while a preferred embodiment is shown and described, the upper frame assemblies 16 can alternatively have any other suitable configuration.

As best shown in FIG. 13, the illustrated control system or assembly 20 includes the electric blower 22 for blowing air into the tanks 14 a, 14 b to raise the tanks 14 a, 14 b, air lines or hoses 96 connecting the blower 22 to each of the tanks 14 a, 14 b, control valves 98 for selectively opening and closing air flow to each of the tanks 14 a, 14 b, one or more level sensors 100, and a controller 102 for selectively operating the blower 22 and the control valves 98 in a desired manner based on input from the level sensors 100 and an operator control panel 104. The illustrated blower 22 is an electric blower and can b of any suitable type. As previously indicated, each tank 14 a, 14 b has an air opening 32 provided with a molded-in air fitting threads through which air is blown into the tank and an outlet 34 through which water and/or air is pushed out of the tank 14 a, 14 b by air incoming through the air opening 32. The blower 22 is preferably connected to the air hoses 96 with a multiple hose coupler 106. One end of each of the air hoses 96 is connected to the multi-hose coupler 106 and the other end of each of the air hoses 96 is connected to the air opening 32 of a separate one of the tanks 14 a, 14 b. The control valves 98 are preferably solenoid air valves but can alternatively be any other suitable type. One of the control valves 98 is provided along each of the air hoses 96 so that the controller 102 can selectively open and close the control valves 98 to permit air flow with any one or more of the air tanks 14 a, 14 b as desired. The level sensor(s) 100 provides an indication to the controller 102 as to how level the watercraft is, that is, how even the tanks 14 a, 14 b are being raised or lowered so that adjustments to one or more of the tanks 14 a, 14 b can be made if necessary to level the watercraft, The illustrated level sensor 100 is of the accelerometer type but any other suitable level sensor can alternatively be utilized. A suitable power source 107 provides electric power to the controller 102, the blower 22, and the control valves 98. The controller 102 is operably connected to the blower 22, the control valves 98, the level sensor(s) 100, and the control panel 104, and is configured to perform all the operations and functions disclosed herein. It is noted that while a preferred embodiment is shown and described, the control system 20 can alternatively have any other suitable configuration.

The illustrated controller 102 with the control panel 104 is mounted on an adjustable base or controller stand 108 which provides adjustment of both controller orientation and controller height. The illustrated controller stand 108 extends thorough an opening midway along one of the walkways 84 on one side of the watercraft lift 10 so that it can be positioned alongside a dock, mooring, or the like (best shown in FIG. 18). FIG. 14 shows the illustrated base stand 108. It is noted that while a preferred embodiment is shown and described, the base stand 108 can alternatively have any other suitable configuration.

As best shown in FIG. 15, the illustrated control panel 104 is provided on a door of controller box 110 which contains the controller 102 and a power switch 112 (shown in FIG. 16) for the control system 20. The illustrated control panel 104 includes button controls, tank indicator lights, and status indicator lights. The illustrated button controls include an up button 114 that raises the watercraft lift 10, a stop button 116 that stops all operations and resets an alarm, a down button 118 that lowers the watercraft lift 10, and a manual button 120 that engages manual control of the watercraft lift 10. The illustrated tank indicator lights includes a front port valve indicator light 122, a rear port valve indicator light 124, a front starboard valve indicator light 126, and a rear starboard valve indicator light 128 each located, on a depiction of the watercraft lift 10, The valve indicator lights 122, 124, 126, 128 are illuminated only when the control valves 98 are open. The illustrated status indicator lights include a power indicator light 130, a manual indicator light, 132 a level indicator light 134, a sensor indicator light 136, and an alarm indicator light 138. The power indicator light 130 is illuminated and pulsing when the control panel 104 is powered. The manual indicator light is illuminated when the controller 102 is in manual mode. The level indicator light 134 is illuminated or flashing depending on lift angle such as, for example but not limited to, solid green at +/−0.5 degrees, slow flashing green at +/−2 degrees, fast green flashing at +/−5 degrees, and flashing red at greater than 8 degrees. The sensor status indicator light 136 is illuminated or flashing depending on the level sensor status such as, for example but not limited to, solid green during normal operation and red flashing during communication error. The alarm indicator light 138 is illuminated red if the lift angle is ever greater than 8 degrees such that the lift 10 must be manually leveled.

To raise a boat on the lift 10, with the tanks submerged, the boat is floated into the established pick up position on the lift between the walkways 84. Safety lines should then be tied off and everyone should be off the boat. With power on, the up button 114 is pressed so that air begins to be blown into all of the tanks 14 a, 14 b which pushes the water in the tanks 14 a, 14 b out through the tank outlets 34. As the water is pushed out of the tanks 14 a, 14 b, the tanks 14 a, 14 b begin to rise out of the water to raise the lift 10 and the boat supported thereon. Once the lift 10 is fully raised and there is no longer water in the tanks 14 a, 14 b, air bubbles exiting each of the tanks 14 a, 14 b become visible. The stop button 116 is then pressed to shut off the blower 22 and dose the control valves 98. Power is then shut off by pressing the power button 112. The buoyancy created by the air trapped in the tanks 14 a, 14 b maintains the lift 10 in the raised position with the boat supported thereon. To lower the lift 10 and the boat supported thereon, once power is on, the down button 118 is pressed. The controller 102 opens the control valves 98 so that air is vented from the tanks 14 a, 14 b to atmosphere as the weight of the lift 10 and the boat supported thereon forces air out of the tanks 14 a, 14 b through the air hoses 96. After the tanks 14 a, 14 b fully submerge to lower the lift and the boat supported thereon, power is shut off and the safety lines can be untied and the boat can be walked off of the lift 10. Once the boat clears the lift, 10, everyone can board the boat. If at any time the boat needs to have the level adjusted, the manual button 120 must be pressed to enter manual mode. hi the manual mode, the manual indicator light 132 is illuminated green. One or more tank indicators lights 122, 124, 126, 128 will also be illuminated. Each additional press of the manual button 120 cycles through different combinations of the tanks 14 a, 14 b. When the desired tank indicator(s) 122, 124, 126, 128 is/are illuminated, the up or down button 114, 118 is pressed to raise or lower the selected tanks 14 a, 14 b. To exit the manual mode, the stop button 116 is pressed and the manual indicator light 132 is no longer illuminated.

The illustrated watercraft lift 10 can be tied to a boat dock, a standard mooring structure, or the like. FIG. 17 shows the watercraft lift 10 tied to a boat dock submerged so that it is ready to load the watercraft onto the watercraft lift FIG, 18 shows the watercraft lift 10 tied to a standard mooring and floating with a watercraft thereon.

FIG. 19 illustrates a variation of the above-described watercraft lift 10A wherein an additional pair of tanks 12 secured together by a lower frame assembly 16 has been added for a total of three pairs of tanks 12 and a total of six of the tanks 14 a, 14 b. The additional pair of tanks 12, provides additional lifting capacity and/or lifting length for larger watercraft. This first variation of the watercraft lift 10A illustrates that the watercraft lift is a modular design that can be easily adapted for use with a wide variety of watercraft sizes using common components.

FIG. 20 illustrates another variation of the above-described watercraft lift 10B wherein two additional pairs of tanks 12 each secured together by a lower frame assembly 16 has been added for a total of four pairs of tanks 12 and a total of eight of the tanks 14 a, 14 b. The additional two pairs of tanks, 12 provides additional lifting capacity and/or lifting length for yet even larger watercraft. This second variation of the watercraft lift 10 further illustrates that the watercraft lift 10B is a modular design that can be easily adapted for use with a wide variety of watercraft sizes using common components.

It is noted that each of the features of the various disclosed embodiments of the present invention can be utilized in any combination with each of the other disclosed embodiments of the present invention.

From the above disclosure it can be appreciated that the free-floating watercraft lifts according to the present invention provide improvements over the lifts of the prior art in that they are: (1) designed for use in both salt or freshwater; (2) easily adjustable for different water craft widths; (3) easily collapsed when fully assembled for easy transportation; (4) designed to maintain a level lifting structure and frame; and (5) modular to provide capacities from 6,000 lbs. to 30,000 pounds depending of the quantity of tank units used. Additionally, the above disclosure illustrates that the watercraft lift can be constructed so that the lateral distance between the tanks can be adjusted so that the overall width of the watercraft lift is small enough that the watercraft lift can be shipped or transported on a standard 8 foot wide shipping trailer even when fully assembled. Furthermore, the watercraft lift preferably utilizes clevis pins and hairpin clips for quick assembly and adjustment

The preferred embodiments of this invention can be achieved by many techniques and methods known to persons who are skilled in this field. To those skilled and knowledgeable in the arts to which the present invention pertains, many widely differing embodiments will be suggested by the foregoing without departing from the intent and scope of the present invention. The descriptions and disclosures herein are intended solely for purposes of illustration and should not be construed as limiting the scope of the present invention. 

What is claimed is:
 1. A free-floating watercraft lift comprising, in combination: a plurality of pairs of tanks each having a first tank and a second tank, wherein the first and second tanks of each pair of tanks are laterally spaced-apart and facing one another; a plurality of lower frame assemblies, each one of the lower frame assemblies connecting the first tank and the second tank of a separate one of the pairs of tanks; first and second upper frame assemblies, the first upper frame assembly connecting each of the first tanks of the plurality of pairs of tanks and the second upper frame assembly connecting each of the second tanks of the plurality of pairs of tanks; and a control system comprising at least one blower for selectively providing air to each of the first and second tanks of the plurality of pairs of tanks.
 2. The free-floating watercraft lift according to claim 1, further comprising a pair of horizontal and laterally spaced-apart bunks supported by each of the plurality of lower frame assemblies.
 3. The free-floating watercraft lift according to claim 1, wherein each of the lower frame assemblies include a first tank frame secured to the first tank and a second tank frame secured to the second tank, and a pair of horizontal and spaced-apart bunk arms each extending between the first tank frame and the second tank frame.
 4. The free-floating watercraft lift according to claim 3, wherein each of the bunk bars is clamped to each of the first and second tank frames by at least one clamp assembly so that a lateral distance between the first and second tanks is adjustable.
 5. The free-floating watercraft lift according to claim 3, further comprising a pair of spaced-part bunk brackets secured to each of the bunk arms, and a pair of horizontal and laterally spaced-apart bunks supported by the bunk brackets.
 6. The free-floating watercraft lift according to claim 5, wherein the bunk brackets are each secured to the bunk arms with a pin and spring clip, the pin extending through a selected one of a plurality of spaced-apart openings along the bunk arms so that the lateral spacing of the bunk brackets is adjustable.
 7. The free-floating watercraft lift according to claim 3,wherein each of the first and second tank frames includes two first frame members and one second frame member, the first frame members are horizontal, laterally extending, and secured to a separate end of the tank, and the second frame member is horizontal and extending between the two first frame members at an inner side of the tank.
 8. The free-floating watercraft lift according, to claim 3, wherein each of the bunk bars are received in one of the first frame members of each of the first and second tank frames in a telescoping manner.
 9. The free-floating watercraft lift according to claim 3, wherein each of the bunk bars is clamped to one of the first frame members of each of the first and second tank frames h at least one clamp assembly so that a lateral distance between the first and second tanks is adjustable.
 10. The free-floating watercraft lift according to claim 9, wherein the at least one clamp assembly is secured to the first frame member with a pin and spring clip, the pin extending through a selected one of a plurality of spaced-apart openings along the first frame member.
 11. The free-floating watercraft lift according to claim 1, wherein the first upper frame assembly includes a pair of horizontal and laterally spaced-apart elongate first beams extending across and secured to each of the first tanks, and the second upper frame assembly includes a pair of horizontal and laterally spaced-apart elongate second beams extending across and secured to each of the second tanks.
 12. The free-floating watercraft lift according to claim 11, wherein the first beams extend across a top of each of the first tanks, and the second beams extend across a top of each of the second tanks.
 13. The free-floating watercraft lift according to claim 11, wherein the first upper frame assembly further includes at least one first walkway plank secured to the first beams to form a walkway over each of the first tanks, and the second upper frame assembly further includes at least one second walkway plank secured to the second beams to form a walkway over each of the second tanks.
 14. The free-floating watercraft lift according to claim 13, wherein the at least one first walkway plank is secured to the first beams by a plurality of horizontal and laterally-extending bushings inwardly extending from each of the first beams and a plurality of brackets secured to the at least one first plank and having horizontally-extending slots open at one end with the bushings therein to limit movement of the at least one first walkway plank relative to the first beams in each direction except a horizontal and longitudinal direction, and the at least one second walkway plank is secured to the second beams by a plurality of horizontal and laterally-extending bushings inwardly extending from each of the second beams and a plurality of brackets secured to the at least one second plank and having horizontally-extending slots open at one end with the bushings therein to limit movement of the at least one second walkway plank relative to the second beams in each direction except a horizontal and longitudinal direction.
 15. The free-floating watercraft lift according to claim 14, wherein there is a plurality of the first walkway planks, and there is a plurality of the second walkway planks.
 16. The free-floating watercraft lift according to claim 1, wherein there are two of the pairs of tanks.
 17. The free-floating watercraft lift according to claim 1, wherein there are at least three of the pairs of tanks.
 18. The free-floating watercraft lift according to claim 1, wherein each of the first and second tanks are generally L shaped such that a height of the laterally outward side is greater than the height of the laterally inward side.
 19. The free-floating watercraft lift according to claim 18, wherein each of the first and second tanks includes a generally flat and horizontal top support surface along a laterally outward side that is upward facing to provide a support for one of the first and second upper frame assemblies, and generally flat and horizontal lower support surfaces along forward and rearward sides that are upward facing to provide support for the plurality of lower frame assemblies, and wherein the lower support surfaces are located between a top and a bottom of the first and second tanks.
 20. A free-floating watercraft lift comprising, in combination: a plurality of pairs of tanks each having a first tank and a second tank, wherein the first and second tanks of each pair of tanks are laterally spaced-apart and facing one another; wherein each of the first and second tanks are generally L shaped such that a height of the laterally outward side is greater than the height of the laterally inward side; a plurality of lower frame assemblies, each one of the lower flame assemblies connecting the first tank and the second tank of a separate one of the pairs of tanks; wherein each of the lower frame assemblies include a first tank frame secured to the first tank and a second tank frame secured to the second tank, and a pair of horizontal and spaced-apart bunk arms each extending between the first tank frame and the second tank frame; first and second upper frame assemblies, the first upper frame assembly connecting each of the first tanks of the plurality of pairs of tanks and the second upper frame assembly connecting each of the second tanks of the plurality of pairs of tanks; wherein the first upper frame assembly includes a pair of horizontal and laterally spaced-apart first beams extending across and secured to each of the first tanks, and the second upper frame assembly includes a pair of horizontal and laterally spaced-apart elongate second beams extending across and secured to each of the second tanks; wherein each of the first and second tanks includes a generally horizontal top support surface along a laterally outward side that is upward facing for the beams of the first and second upper frame assemblies, and horizontal lower support surfaces along forward and rearward sides that are upward facing for the first and second tank frames, and wherein the lower support surfaces are located between a top and a bottom of the first and second tanks; and a control system comprising at least one blower for selectively providing air to each of the first and second tanks of the plurality of pairs of tanks. 